Key Financial Data Of Reporting Company
| Concept | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||||||||
| Net sales | — | — | 
                                                19,932,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                18,553,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,781,688,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,429,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,618,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,747,349,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,379,915,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,567,414,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,012,514,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,153,646,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | 
                                                105,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                218,268,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                349,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                331,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                637,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                570,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                637,159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                625,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,508,660,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,533,827,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | 
                                                21,103,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                648,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                666,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                631,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,440,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,019,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | 
                                                5,516,335
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,516,335
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                5,516,335
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,516,335
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                5,516,335
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | 
                                                4,376,741,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,635,430,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                4,531,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,804,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,272,408,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,994,030,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,404,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,680,410,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,422,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,724,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                20,000,834,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,829,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                20,107,721,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,793,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,826,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,136,278,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                18,196,352,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,948,765,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,849,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,580,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                793.80
                                                
                                             | — | 
                                                840.72
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                821.95
                                                
                                             | 
                                                871.46
                                                
                                             | — | 
                                                774.88
                                                
                                             | 
                                                724.39
                                                
                                             | — | — | — | 
                                                617.46
                                                
                                             | 
                                                667.51
                                                
                                             | 
                                                620.75
                                                
                                             | — | — | 
                                                675.53
                                                
                                             | 
| Dividend paid per share | — | — | — | — | — | — | — | — | — | 
                                                14.00
                                                
                                             | 
                                                28.00
                                                
                                             | — | — | — | 
                                                21.00
                                                
                                             | — | — | — | 
                                                14.00
                                                
                                             | — | — | — | — | 
                                                7.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — | — | — | — | — | — |  |  | — | — | — |  | — | — | — |  | — | — | — | — |  | — | — | 
| Basic earnings (loss) per share | — | — | 
                                                -17.58
                                                
                                             | — | — | — | — | — | — | 
                                                3.83
                                                
                                             | 
                                                117.63
                                                
                                             | 
                                                114.13
                                                
                                             | — | — | 
                                                120.83
                                                
                                             | — | — | 
                                                108.32
                                                
                                             | 
                                                114.55
                                                
                                             | 
                                                111.91
                                                
                                             | — | — | — | 
                                                -443.48
                                                
                                             | 
                                                -446.07
                                                
                                             | — | 
| Diluted earnings per share | — | — |  | — | — | — | — | — | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.219
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.223
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                0.225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.231
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.215
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.209
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.187
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.194
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.192
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.200
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | 
                                                -0.022
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                0.004
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.143
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.148
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.161
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.171
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.181
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.493
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.526
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                102.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                4.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | — | — | — | — | — | 
                                                3.658
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.238
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.174
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                548,949,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                699,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,063,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,730,629,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -717,838,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -1,092,325,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -687,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -1,494,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -316,821,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -369,753,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                89,010,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                50,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,333,509,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,298,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                978,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                1,361,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,254,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,640,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,533,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                653
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                610
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                369
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                193
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                378
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                726
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                673
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                699
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                751
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                778
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                735
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                781
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                469
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                446
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                331
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                93
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                93
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                354
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                22
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                431
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                408
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                379
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                404
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                315
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                306
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                255
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                247
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | — | — | 
                                                1.227
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.677
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.584
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.028
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.114
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | — | 
                                                1.895
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.973
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.428
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.387
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.393
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |